首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   214篇
  免费   1篇
  国内免费   1篇
化学   55篇
晶体学   2篇
数学   2篇
物理学   157篇
  2022年   2篇
  2021年   1篇
  2019年   2篇
  2018年   2篇
  2017年   3篇
  2016年   4篇
  2015年   6篇
  2014年   1篇
  2013年   6篇
  2012年   7篇
  2011年   7篇
  2010年   4篇
  2009年   3篇
  2008年   13篇
  2007年   23篇
  2006年   13篇
  2005年   24篇
  2004年   19篇
  2003年   13篇
  2002年   11篇
  2001年   11篇
  2000年   3篇
  1999年   8篇
  1998年   5篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1990年   1篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1963年   4篇
排序方式: 共有216条查询结果,搜索用时 15 毫秒
211.
A distinct peak is observed in the pi +/- psi' invariant mass distribution near 4.43 GeV in B-->K pi +/- psi' decays. A fit using a Breit-Wigner resonance shape yields a peak mass and width of M=4433+/-4(stat)+/-2(syst) MeV and Gamma=45-13+18(stat)-13+30(syst) MeV. The product branching fraction is determined to be B(B 0-->K -/+Z+/-(4430)) x B(Z+/-(4430)-->pi+/-psi')=(4.1+/-1.0(stat)+/-1.4(syst)) x 10(-5), where Z+/-(4430) is used to denote the observed structure. The statistical significance of the observed peak is 6.5 sigma. These results are obtained from a 605 fb(-1) data sample that contains 657 x 10(6) BB pairs collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider.  相似文献   
212.
We report on a search for the doubly Cabibbo suppressed decay B+-->D*+pi0, based on a data sample of 657x10(6) BB pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find no significant signal and set an upper limit of B(B+-->D*+pi0)<3.6x10(-6) at the 90% confidence level. This limit can be used to constrain the ratio between suppressed and favored B-->D*pi decay amplitudes, r<0.051, at the 90% confidence level.  相似文献   
213.
We report the first measurement of CP-violation parameters in B0-->rho0gamma decays based on a data sample of 657x10(6)BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain the time-dependent and direct CP-violating parameters, Srho0gamma=-0.83+/-0.65(stat)+/-0.18(syst) and Arho0gamma=-0.44+/-0.49(stat)+/-0.14(syst), respectively.  相似文献   
214.
We report a measurement of the CP-violating parameters in B;{0}-->K_{S}{0}K_{S}{0} decays based on a data sample of 657x10{6} BB[over ] pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e;{+}e{-} collider. In this Letter, one neutral B meson is fully reconstructed in the B;{0}-->K_{S}{0}K_{S}{0} decay mode, and the flavor of the accompanying B meson is identified by its decay products. The CP-violating parameters are measured from the asymmetry in the distributions of the proper-time interval between the two B decays: S_K_{S}{0}K_{S}{0}}=-0.38_{-0.77}{+0.69}(stat)+/-0.09(syst) and A_{K_{S}{0}K_{S}{0}}=-0.38+/-0.38(stat)+/-0.05(syst).  相似文献   
215.
Abstract Single crystals of new open-framework lanthanide sulphate nitrite La(NO2)(SO4)(H2O) has been synthesized, in the presence of 2,6-diformyl-4-chlorophenol. His structure has been determined by X-ray diffraction data: the complex crystallizes in the tetragonal system, space group P43, with a = 7.0028(2) (?), b = 7.0028(2) (?), c = 11.8341(4) ?, V = 580.34(3) ?3, Z = 4, D c = 3.582 Mg m−3. The three-dimensional (3D) framework of this compound is built up by the linkages of lanthanide atoms and the oxygen atoms of the sulphate and nitrite groups. The lanthanum atom is 9-fold coordinated. The structure is unfamiliar in lanthanide chemistry and this compound represents the first example of nitrite lanthanide sulphate complex. Graphical Abstract An unfamiliar structure in lanthanide chemistry represented by the first example of nitrite lanthanide sulphate complex is described.   相似文献   
216.
Supersymmetry is formulated within a functional approach of euclidean quantum field theory. The rǒle of the euclidean Lie superalgebra and its relation to the Poincaré Lie superalgebra are investigated in detail. As example we study the Wess-Zumino model in two dimensions.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号